I still don't understand the discussion about governor-springs. The injection pumps on my Fords and GMs (Stanadyne DB2s) all have external governor adjuster screws. Very easy to change the governed RPM and no dissassembly or parts required. Also, I still don't know what the "groove in governor shaft" is all about.
Can someone explain? I've had many of these pumps apart, and I don't know what part is being referred to.